The binding of ConA and other lectins to surface glycoproteins: a comparison of a subcutaneous tumour and its liver metastases.

The glycoprotein composition of a transplantable subcutaneous lymphosarcoma (1 degree) and its liver metastases (2 degrees) have been examined in Triton X-100 extracts obtained from tissue, single cells and membrane preparations by using electrophoresis and treatment with radio-labelled lectins. No consistent differences could be detected in the electrophoretic patterns of 1 degree and 2 degrees tumour using RCA-60 or gorse. Small differences were detected using Concanavalin A; all but one of these were eliminated as being due to differential host contamination. A minor band of 178,000 daltons molecular weight was found in 1 degree tissue, cells and membranes that was absent in extracts from 2 degrees tumour. Percoll density gradient separations suggested that this glycoprotein belonged to a small subpopulation of cells; their identity remains uncertain. The band was still detected when tumour was grown from direct liver implants, but it disappeared when this growth metastasized to another lobe. The results provide evidence that metastasis can be accompanied by a very subtle change in the tumour glycoprotein profile. Such a change may have important consequences for host/tumour interactions and subsequent metastatic spread.